Des Grieux and Manon, having both travelled to America on the prisoners' boat, are walking, shadows of themselved, through "the desert of Louisiana". After Des Grieux has left to look for water. Manon, thinking he has forsaken her entirely, falls into delirium.Des Grieux comes back only to witness her last moments. The scene is treated like a mirage with vague memories of Manon's life (seen in vignettes throughout the opera): the church steeple of Act I, the chair of Act II, and the floor of the opera in shambles.